where \(n,i,j,k = 1,2\) , and the summation over the repeated indices is assumed [1]}. And there are
others aspects of the SP equation have been addressed in the literature, including integrable semi-discrete and full-discrete analogues [2]},
well-posedness of the Cauchy problem [3]}, [4]} and Riemann-Hilbert approach [5]}. Using the method of testing by wave packets, Okamoto prove the unique global existence of small solutions to the SP equation (REF ) when the small initial data \(u_0\)  [6]}.
